A technique of making a processing device (such as a microprocessor) capable of executing one or more processes execute an interrupt process each time the interrupt process is caused is conventionally known. In such a technique, if an interrupt process is caused when the microprocessor is in an idle state in which the microprocessor is not executing any processes, the microprocessor changes from the idle state to an active state in which the microprocessor executes the interrupt process. The microprocessor then changes to the idle state again after executing the interrupt process.
In this case, power is consumed when the microprocessor changes from the idle state to the active state or from the active state to the idle state because processing associated with the state change is caused. Therefore, the technique of making a processor execute an interrupt process each time the interrupt process is caused is disadvantageous in increased power consumption because the number of state changes of the microprocessor is large.